Building a submarine : LUSENET : Junkyard Wars : One Thread

Hello, I'm wondering if anyone has experience in, or has attempted, or has knowledge of building a submarine. I've had this idea for many years, and after some intense planing I've decided to go ahead with it. I have most of the systems worked out, and I'll be building a working model to test them. For isntance, there is the problem of breathing. I plan to pump the air (using small electric pump) through a sodium hydroxide solution to remove CO2. Is there an easier way? What do they use on real submarines? I've decided to use LPG to displace the water in the flood tanks, as the gas is very cheap, and I have a large cylinder. It is relatively low pressure, so I believe that the sub's diving depth (ie. pressure) will be limited to the pressure of the LPG tank. If I dived too deep, the LPG wouldn't displace the water in the flood tanks. Am I correct in this assumption? For additional oxygen for the crew, I plan to have a scuba tank on board supplying air when needed, or perhaps pure oxygen to enrich the depleted air (from hydrogen peroxide or from a cylinder). I'm still undecided about whether the sub will have a pressure hull or not. Without one, it is essentially a diving-bell with propulsion. and a means to surface and dive. This has the draw-back of 1) the water rising in the sub unless additional pressure is added inside the sub as it dives 2) only a bottom hatch is possible - the crew has to enter the sub from underwater, and therefore get wet. Propulsion is also a bit of a problem. A pressure hull would be needed for a petrol engine to be able to breathe, unless the engine was in a separate compartment. Would man-power be feasable, or would it require too much energy (ie. air)? I'm not looking at making huge open-sea voyages, just cruising round the beaches and bays. It'll be a 2-man craft, so I figured about 3 cubic metres of spaces inside the sub will do. For this to work, the sub will need to be 3 tons or more to be able to submerge. I was thinking of making it out of wood, but I'm not sure if wood could hold 3 tons. Further plans that havn't been worked out fully include having surface to surface missiles in watertight silos, as well as torpedos. Does anyone know how to make the sub sonar elusive? Maybe have all surfaces at oblique angles. I wouldn't like to run into opposition by the navy and get torpedoed. Thanks for your help. -Rake

-- Rake Maan (, January 08, 2004


actually what i would do is find an old jetski engine (becase they emit exaust through the propulsion unit anyways)also with a jetski engine the sub is driven by a jet of water. (prop is in a pipe thus shooting water instead of having a prop exposed for damage). and for the sonar,id use a fish finder (lol)not as detailed as real sonar but it works. but actually dont use sonar get a under water camera so u can not too sure about the breathing systems ill leave that to you.but for ground to water missiles i can do. . . get a model rocket, fill the tip of the cone with gun powder and seal it with epoxy.then drill a little into the top of the rocket engine and epoxy a fuse into the powder you drilled in the top.then get a cheap r/c car and just detach the 2 power wires connected the the elec. motor and attach to rocket ignitor strip.put it in a canister with a paper cap,(put a pin on the tip of the rocket)and somehow release the canister from the vessel and when you hit go on the remote control the rocket launches and when it burns out the fuse ignites the bomb (warhead) in the wait for it to float to the top first,but you can launch after releasing from your vessel.btw the navy wont mess with ur vessel they'll think ur a manatee or a big sting ray.

(ask me if you need any help with propulsion or weapon systems ok! e_mail me personally)

-- god among insects (, January 12, 2004.

1> subs are more dangerous then airoplanes, dont do it! 2> lpg for balast tanks? if anything leaks, your sitting in a bomb.. 3> still dont do it.. 4> if you realy insist have a look at a comunity of amateur submarine builders. 5> DONT DO IT!!

-- Jasper Greve (, April 07, 2004.


-- steven karkenny (, April 21, 2004.

Moderation questions? read the FAQ